The driving of an aircraft on the ground, and in particular the control of the aircraft around its yaw axis, is generally provided by controlling the steering angle of the nose gear wheel, by the orientation of the rudder, and in addition by a differential braking assembly able to exert a braking differential between a left main landing gear and the right main landing gear to generate the yaw movement. The control of the aircraft around its yaw axis may further be done using electric motors driving the wheels of the main landing gear, at different speeds and/or by applying a thrust differential between the left engine and the right engine.
Various control means are known to command these different lateral movement devices.
In particular, some aircraft include three separate control means each acting on one of the aforementioned lateral movement devices. These control means for example consist of a tiller, a rudder bar and independent brake pedals.
The tiller is a control wheel whose rotation makes it possible to cause a corresponding modification of the steering angle of the wheel.
The rudder bar is intended to control the rudder. In particular, the rudder bar generally includes a left pedal, the movement of which is intended to control a left turn, and a right pedal, the movement of which is intended to control a right turn.
The brake pedals include a left brake pedal and a right brake pedal, the actuation of which is intended to command braking of the left or right main landing gear, respectively, therefore a turn to the left or to the right, respectively.
The brake pedals are for example mounted on the rudder bar. Thus, each rudder bar pedal is movable along a first degree of freedom, for example in translation, associated with a command of the rudder, and along a second degree of freedom, for example in rotation around an axis orthogonal to the translation direction of the pedal, associated with a command of the differential braking assembly.
Nevertheless, the guiding of an aircraft on a runway may prove delicate, in particular due to the presence of obstacles (buildings, vehicles, other aircraft, etc.) on the runway, the variable adhesion state of the latter and encountered weather conditions (crosswind, for example).
To assist the pilot in guiding the aircraft on the ground, it is known from document U.S. Pat. No. 7,592,929 to display, on a viewer, a depiction of the runway on which an element is superimposed depicting the current lateral trajectory of the aircraft.